Dual-function spring

ABSTRACT

An injection device for dispensing a product, the injection device including a moveable element which is moved for a dispensing operation, a spring, a product container holder and a product container, wherein the spring pushes against the moveable element to move the moveable element to an initial position after the dispensing operation has ended and against the product container to seat the product container in the product container holder.

CROSS-REFERENCED RELATED APPLICATIONS

This application is a continuation of International Patent ApplicationNo. PCT/CH2009/000078 filed Feb. 26, 2009, which claims priority toGerman Patent Application No. 10 2008 011 885.0 filed Feb. 29, 2008, theentire contents of each of which are incorporated herein by reference.

BACKGROUND

The present invention related to devices for injecting, infusing,administering, dispensing or delivering a substance, and to methods ofmaking and using such devices. More particularly, the present inventionrelates to an injection device for administering a substance or productsuch as a medicament or therapeutic substance, e.g. insulin, growthhormone, etc.

The idea of coupling an ampoule (which also may be referred to and/orthought of as a container, carpoule, vial or the like) containing aproduct to or in an injection device is known from the prior art.Securing an ampoule in a stationary seating, for example in an ampouleholder, when attached to the injection device is also known. In somecases, the ampoule may be screwed into the holder, and the securing orholding may be achieved by a clamping action wherein the productcontainer accommodated in the ampoule holder is clamped between thedistal (forward) end of the ampoule holder and a stop which acts on thedistal end of the ampoule.

SUMMARY

An object of the present invention is to provide an injection device towhich a product container can be secured in a reliable, efficient andeconomic manner.

In one embodiment, the present invention comprises an injection devicefor dispensing a product, the injection device including a moveableelement which is moved for a dispensing operation, a spring, a productcontainer holder and a product container, wherein the spring pushesagainst the moveable element to move the moveable element to an initialposition after the dispensing operation has ended and against theproduct container to seat the product container in the product containerholder.

In one embodiment of an injection device according to the presentinvention, the device comprises coupling element, a product container,and a spring between the coupling element and the product container, thespring biasing or urging the coupling element in one direction and theproduct container in the other, i.e. opposite, direction.

In some embodiments, the present invention comprises an injection devicewhereby an injection may be administered manually by the user or maytake place automatically. For example, a user of an embodiment of thedevice designed for automatically dispensing the product may operate anoperating element which releases a drive element, for example a spring,and the spring force acts indirectly or directly on an output elementand/or pushes the plunger of a product container in a dispensingdirection. The drive element may be a motor, a pyrotechnic propellantcharge or, as in some preferred embodiments of the present invention, aspring, e.g. a mechanical spring. If the drive element is of the typewhich stores energy, in some preferred embodiments the stored energy canbe released by an operating element so that a driving movement can beconverted into an output movement. In some embodiments, the drivingmovement may be a rotating movement, and the output movement may be alinear movement.

In some preferred embodiments, the drive element may be a rotatingspring, e.g. a helical or clock spring, which is wound about thelongitudinal axis of the injection device. For example, the spring maybe supported in a fixed arrangement on the housing in at least onedirection of rotation by one end and connected to the output element ora part which is or can be coupled with the output element by the otherend. Thus, the rotational energy stored in the spring may be convertedinto a driving movement. In some embodiments, it is advantageous to usea strip-shaped helical spring.

In some embodiments, an injection device in accordance with the presentinvention may be disposable. Generally, in such embodiments, a productcontainer inserted or built into the device during production can not bereplaced, and when empty or after the injection device has been used, itis disposed of as a whole together with the product container.

In some embodiments, an injection device in accordance with the presentinvention is designed to be used more than once. This is practical ifthe injection device is fitted with high-quality and/or high-tolerancecomponents designed to make it easy to dispense a product and which maybe too expensive for use with disposable items. In some embodiments, adriving mechanism is incorporated in a drive unit, in which case theproduct container can be attached to the drive unit, and can be detachedfrom the drive unit. An empty product container can be released from thedrive unit, disposed of and replaced by a new one.

In some preferred embodiments, the product container is received and/orseated in a product container holder. The product container holder issleeve-shaped and has an opening through which the product container canbe inserted into the interior of the sleeve. The opening may be disposedlaterally or on an end, e.g. the proximal (rear) end, of the productcontainer holder. At the side, the product container holder may have aregion through which it is possible to see from the outside into theinterior of the container to, for example, ascertain whether a productcontainer has been inserted or to check how full an inserted productcontainer is. The product container holder may have a collar at itsdistal (forward) end, against which the product container sits in anabutting contact in its inserted state. The product container is thenfixedly seated in the product container holder. The product containerholder may have a conical shape, and the product container can be pushedinto it to obtain a fixed seating.

In some preferred embodiments, an injection device in accordance withthe present invention, e.g. the drive unit thereof, may comprise aspring element, such as a mechanical spring, a gas compression spring orother elastic means, which acts on or pushes on the product container,e.g. the part of the product container relative to which the plunger canbe displaced. In some preferred embodiments, the spring element may pushthe product container into a fixed seating with and/or within theproduct container holder. In some preferred embodiments, the springelement may act in the longitudinal direction of the injection device.

In some embodiments of the present invention, the product container maybe an ampoule or capped vial, for example, and is open at its proximal(rear) end and closed at its distal (forward or front) end. An outputelement of the drive unit may extend through the proximal end into theproduct container to act on a plunger or piston in the container, whichplunger or piston can be displaced relative to the product containerwall. The distal end may incorporate or carry a needle, or may bedesigned so that a needle can be attached, thereby establishing a flowconnection to the interior of the product container due to the fact thatthe needle pierces a septum disposed on the distal end of the productcontainer. In some preferred embodiments, the wall of the productcontainer is cylindrical, and it may be tightly enclosed by thesleeve-shaped product container holder or enclosed with a slightclearance.

In some embodiments, the injection device may have an element which ismoved back into an initial position after a dispensing operation hasended or as it is ending. This may be an operating element which can beoperated by moving it, e.g. by moving it axially along a longitudinalaxis of the injection device. The element may be moved into a dispensingposition as the dispensing operation is being actuated or triggered, inwhich case the direction of movement needed for this purpose is oppositethe direction of movement in which the element can move on terminatingthe dispensing operation. The operating element may be operated by auser of the device to trigger and/or stop dispensing of the product, orit may be released after the product has been dispensed whereby it movesback or automatically returns to its initial position. A lock elementmay be coupled with the operating element so that it is axially locked,at least in one direction and, in some preferred embodiments, in bothdirections.

In some embodiments, the operating element moves back or can be movedback to an initial position after the dispensing operation hasterminated. Thus, an injection device in accordance with the presentinvention may comprise a coupling, e.g. a coupling element whichestablishes or releases a coupling as it is moved. For example, such acoupling element may be coupled with the operating element in at leastone direction and at least for a certain time. The coupling element maypush the operating element in one direction, and in the other, oppositedirection, the operating element may push the coupling element.

In some preferred embodiments, the element which is moveable when adispensing operation is terminated or triggered may be moved back intoan initial position by a spring element when the dispensing operationhas terminated. The spring element may also urge the product containerinto its fixed seating. In some preferred embodiments, the springelement is a helical spring, which may be wound from a wire-likematerial. The spring element may be disposed parallel and/orconcentrically with the longitudinal axis of the injection device.

In some preferred embodiments, a spring in accordance with the presentinvention may fulfil a dual function, namely that of pushing the productcontainer into its fixed seating and that of providing the requisiteforce for the element which moves back to an initial position when adispensing operation has terminated. An advantage of using a spring tourge or push the product container into its fixed seat or location isthat it offers an easy way of compensating for variations in thelongitudinal tolerances of product containers. It also allows aninjection device to be used with product containers produced bydifferent manufacturers. Another advantage of using a spring with a dualfunction is that it may replace or avoid the use of two separatesprings, one of which pushes the product container and the other ofwhich pushes the operating element, thereby reducing costs.

In some embodiments, the element which can be moved back to its initialposition after the dispensing operation has terminated may prevent, e.g.lock, a movement of the output element relative to the housing when itis in a coupled state and unlock, i.e. release it, relative to thehousing when it is in an uncoupled state. In some preferred embodiments,this locking effect is provided by an anti-rotation lock. In somepreferred embodiments, to effect a dispensing operation, the moveableelement, which may be a part of a coupling, is moved out of the coupledengagement for a dispensing operation. To this end, it may be moved outof the coupled engagement by the operating element, in which case theoperating element is operated, e.g. pushed, as a result of which theelement is moved out of the coupled engagement against the spring forceof the spring element. The element may be able to be moved axiallyrelative to a housing and/or the drive unit of the injection device, butnot rotate. The dispensing movement of the output element, which may bea plunger rod and have a freely rotatable but axially fixed flange onits end, can be effected relative to the housing or a locating elementwhich moves into or is positioned in the output element. In someembodiments, the locating element may locate in (or be received in orcoupled to) the output element so that the output element can be movedaxially relative to the locating element in and/or opposite thedispensing direction, e.g. turned or screwed. For example, the locatingelement may have an internal thread which locates in and/or complementsan external thread of the output element. Alternatively, the outputelement may be longitudinally guided by the locating element. Thelocating element may be secured so that it is not able to rotaterelative to the housing and may also be secured so that it can not moveaxially, although this is not necessarily the case. In some preferredembodiments, the locating element is able to move axially relative tothe housing, in which case it is secured to the housing so that it cannot move axially when a product container has been inserted and securedon the drive unit.

In some preferred embodiments, the output element which acts on theproduct to be dispensed to dispense the product, e.g. via the plunger,is coupled with the re-settable element in such a way that itsdispensing movement is locked when the product container is notattached. This means that triggering is not possible if a productcontainer has not been inserted.

In some preferred embodiments, the output element is unlocked and caneffect a rotating movement in the state in which a product container hasnot been inserted so that the output element can be screwed back, e.g.in the proximal direction, by a rotating movement of the output elementinto the drive unit if a product container has not been inserted or if aproduct container holder has been removed. In some preferredembodiments, the thread by which the locating element locates in theoutput element has a pitch which does not cause any frictionalresistance of the thread when placed under axial load. When pressure isapplied to the output element, e.g. to the flange thereof, in theproximal direction, it is able to move easily in the proximal directionwithout the user having to apply a rotating movement to the outputelement. If a product container has been removed or if a productcontainer holder has been removed, the locating element can be movedbetween a first position and a second position, and in the firstposition, the output element is uncoupled from the element so that theoutput element is able to move in or opposite the dispensing direction.Providing the product container or the product container holder has beenattached to the drive unit, the locating element is moved into itssecond position, thereby preventing a rotating movement of the outputelement. For example, the locating element may be moved by the productcontainer or by the product container holder directly or indirectly, forexample by the fixing device. The product container or the productcontainer holder may constitute or incorporate a part of the fixingdevice. A movement out of an unsecured state into the secured state,e.g. a rotating movement of the product container or product containerholder, in some preferred embodiments, a combined rotating-axialmovement, causes the locating element to move.

In some preferred embodiments, the locating element is coupled with thefixing device so that when the product container or product containerholder is attached or released, it is moved axially on or by the driveunit. The locating element may be connected in an axially fixedarrangement to a coupling element, such as a coupling sleeve, which isin turn able to rotate relative to the locating element. The couplingelement may be sleeve-shaped and surround the output element or at leastcooperate with the output element so that the output element is able tomove axially relative to the coupling element but not rotate. Thecoupling element may locate in a longitudinal groove of the outputelement. The coupling element may be part of a transmission whichtransmits the torque of the drive element to the output element. Anotherelement may be connected to the drive element in a fixedtorque-transmitting arrangement, such as a drive shaft which is or canbe coupled with the output element, due to the fact that the drive shaftcan be coupled with the output element via a coupling which can beaxially engaged with and released from the output element. To this end,the coupling element and the drive shaft may form part of the coupling,which can be coupled and uncoupled.

In some embodiments, the coupling element may also have projections,which are moved into engagement or out of engagement with there-settable element depending on the desired operating mode.

In some preferred embodiments, the spring element fulfilling the dualfunction is disposed between a re-settable element and the productcontainer. It may be advantageous if the re-settable element issubjected to a force acting in the proximal (rearward) direction by thespring and the product container is subjected to a force acting in thedistal (forward) direction by the spring. The spring element may actdirectly or indirectly on the product container. In some preferredembodiments, the spring acts via one or more parts disposed between theproduct container and the spring element. For example, a retainer orretaining element may be disposed between the product container andspring element, which pushes on the proximal end of the productcontainer by its distal end. The retaining element may have an axialstop which prevents the spring element from fully relaxing when aproduct container is being removed or has been removed. For example, thestop may move into an abutting contact with the locating element so thatthe retaining element is moved axially by a distance which is limitedbut long enough to compensate for longitudinal tolerances of the productcontainer. The retaining element may be displaceable relative to thelocating element and/or to the housing. The arrangement may be such thatthe spring expends a force on the re-settable element and also on theoperating element for example, when a product container is inserted.

In some embodiments, one or more parts, e.g. at least one other part,may be provided between the spring and operating element, in addition tothe re-settable element, which can be moved by the operating elementand/or by the element which is re-settable by the spring element. Forexample, a bearing may be provided between the operating element and there-settable element, which provides a bearing for the coupling elementtransversely to the longitudinal direction, and/or a threaded sleevewhich can be used to produce a rotating movement for additional parts ofthe injection device, e.g. a dose display or a dose stop for the finaldose, and/or a brake to restrict the driving speed, and/or a driveelement which supplies the driving energy needed to dispense theproduct. These parts may be moved in the distal direction when theoperating element is operated, for example, and in the proximaldirection during the re-setting movement of the spring element. Thisbeing the case, the spring element also fulfils the function of holdingtogether axially adjoining parts or components. In some embodiments, thespring element may also be used to couple and uncouple variouscouplings, i.e. supply coupling forces.

In some embodiments, the spring fulfilling the dual function may be aseparate part or component, or it may be a part formed by a structure orelement adjoining the spring. If a separate spring is provided, it maybe made from a suitable material, e.g. plastic, metal, etc. In someembodiments, if the spring is an integral part of another component, thespring may be made from plastic because it can be injection molded withthe other part. An advantage of this is that it may be possible toreduce costs. Alternatively, in using a metal spring, the element whichthe spring is part of can be cast around it. This may be done by asimple injection casting process. For example, the spring may beintegral with the re-settable element or integral with a supporting ringwhich may be provided as a separate part between the spring andretaining element, or integral with the retaining element which pusheson the product container and/or comprises an axial stop. Another optionis for the retaining element, spring and re-settable element to be of anintegral design.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view illustrating a proximal (rear) part ofan embodiment of an injection device in accordance with the presentinvention,

FIG. 2 is a perspective view of an embodiment of a housing part with aguide track for a bayonet lock and an inserted bayonet sleeve,

FIG. 3 is a perspective view of the bayonet sleeve illustrated in FIG.2,

FIG. 4 is a perspective view of the bayonet sleeve illustrated in FIG. 3with a locating element inserted in it,

FIG. 5 is a perspective view of a bayonet sleeve and product containerholder, which is moved axially into a fixed torque-transmittingengagement,

FIG. 6 is a perspective view of an output element with a flange andspring element,

FIGS. 7A and 7B are, respectively, an exploded diagram and a perspectiveview of one embodiment of a brake mechanism in accordance with thepresent invention,

FIG. 8 is a perspective, exploded diagram of another embodiment of abrake mechanism in accordance with the present invention,

FIG. 9 is a diagram schematically plotting braking force as a functionof angular speed,

FIG. 10 is a diagram illustrating braking action as a function of time,

FIGS. 11A and 11B are, respectively, an exploded view and a perspectiveview of an embodiment of a brake mechanism in accordance with thepresent invention operating on the principle of an eddy current brake,

FIG. 12 is a perspective view of another embodiment of a brake mechanismin accordance with the present invention operating on the principle of acentrifugal brake,

FIG. 13 is an exploded view of another embodiment of a brake mechanismin accordance with the present invention operating on the principle of afluidic brake, and

FIG. 14 is a perspective view of a brake housing from FIG. 13.

DETAILED DESCRIPTION

With regard to fastening, mounting, attaching or connecting componentsof the present invention, unless specifically described as otherwise,conventional mechanical fasteners and methods may be used. Otherappropriate fastening or attachment methods include adhesives, weldingand soldering, the latter particularly with regard to the electricalsystem of the invention, if any. In embodiments with electrical featuresor components, suitable electrical components and circuitry, wires,wireless components, chips, boards, microprocessors, inputs, outputs,displays, control components, etc. may be used. Generally, unlessotherwise indicated, the materials for making embodiments of theinvention and/or components thereof may be selected from appropriatematerials such as metal, metallic alloys, ceramics, plastics, etc.Unless otherwise indicated specifically or by context, positional terms(e.g., up, down, front, rear, distal, proximal, etc.) are descriptivenot limiting. Same reference numbers are used to denote same parts orcomponents.

The injection device illustrated in FIG. 1 comprises a drive unit,which, in some embodiments, can be used more than once, and a productcontainer 27 connected to it, which is accommodated in a sleeve-shapedproduct container holder 16 which can be used multiple times, forexample, and which can be secured to the drive unit with the aid of theproduct container holder 16. The product container 27 can be removedfrom the injection device after it is empty, disposed of and replacedwith a new one. With a view to simplifying the manufacturing andassembly processes, the housing 12 is of a multi-part design comprisinghousing elements 12 a, 12 b connected to or inserted in it, although inprinciple, the housing could also comprise a single part. The productcontainer 16 is attached to the drive unit by a bayonet fitting, whichis formed by the housing 12, product container holder 16 and sleeve 50.The product container holder 16 is covered by a cap 31, which is fittedon the housing 12, and can be removed in preparation for using theinjection device and then fitted back on it.

FIGS. 2 to 5 illustrate elements of the fixing device provided in theexemplary form of a bayonet fitting. The product container holder 16 hasa cam 16 c extending radially outwardly and at its proximal (rear) endface is designed so that it can be connected in a positive fit, i.e. ina fixed torque-transmitting fit, to the distal (forward) end face of thesleeve 50, as illustrated in FIG. 5 where housing part 12 a has beenomitted for illustration purposes. The sleeve 50 has at least one cam 50c extending radially outwardly, which forms a part of a cam (which maybe thought of as comprising cam elements 16 c, 50 c) for the fixingdevice. The cam 50 c locates or is positioned in a guide track 12 eformed in the housing 12, e.g. in housing part 12 a, which has at leastone inclined surface 12 g. When the sleeve 50 is moved in rotation, thesleeve 50 moves axially relative to the housing part 12 a as well asmoving in rotation, due to the locating cam 50 c. As will be describedbelow, the axial movement of the sleeve 50 results in variousadvantageous effects.

To fit the product container 27 on the drive unit, it may be introducedinto the product container holder 16 via the proximal end. The productcontainer holder 16 is then snap-fitted onto the sleeve 50 by an axialmovement resulting in a fixed torque-transmitting fit (FIG. 5), so thatthe cams 16 c are inserted through the opening 12 f (FIG. 2) into theguide track 12 e. FIG. 2 illustrates the bayonet fitting in a lockedstate without the product container holder 16. In an unlocked state inwhich the cams 50 c are disposed in the region of, and axially flushwith the openings 12 f, the product container holder 16 can bepush-fitted. The cams 16 c and 50 c then lie one against the other andform a common cam (FIG. 5). A rotation of the product container holder16 causes the sleeve 50 to be driven. Due to the inclined faces 12 g,the sleeve 50 and the product container holder 16 are also movedaxially. At the end of the rotation, i.e. on reaching the lockedposition, the common cam (comprising cam elements 16 c, 50 c) isdisposed in the region 12 h of the guide track 12 e in which the twocams 16 c and 50 c are axially clamped together by the sides of theguide track 12 e. To this end, the axial width of the guide track in theregion 12 h is approximately as wide as that of the joint cams 16 c, 50c.

As illustrated in FIG. 4, a guide sleeve 26 is accommodated in thesleeve 50, which may also be thought of and/or referred to as thebayonet sleeve. The guide sleeve 26 is connected to the housing 12 sothat it can not rotate but can move axially and is connected to thebayonet sleeve 50 so that it can rotate but can not move axially. As aresult, when the bayonet sleeve 50 is moved from the unlocked to thelocked position and vice versa, the guide sleeve 26 effects alongitudinally guided movement relative to the housing 12.

As may be seen from FIG. 1, a threaded insert 6 is connected and/orlatched to the guide sleeve 26 so that it can not rotate or moveaxially. The threaded insert 6 and guide sleeve 26 may be thought ofand/or referred to as a locating element (comprising insert and sleeveelements 6, 26). The threaded insert 6 has an internal thread 6 a inwhich the external thread 2 a of an output element 2, which might alsobe called a plunger rod in this example, is guided so that when theoutput element 2 is rotated, it is guided by the internal thread 6 a ofthe threaded insert 6 in the proximal direction or in the distal, i.e.opposite, direction, as it is screwed, depending on the direction ofrotation.

On its external face, the output element 2 has a thread 2 a, which isinterrupted by two grooves 2 b extending in the axial direction lyingopposite one another on the circumference. A coupling sleeve 5constituting part of a transmission (comprising elements 7, K2, 5) hastwo projections 5 a, 5 b directed radially inwardly lying opposite oneanother on its distal end which project into the grooves 2 b of theoutput element 2. The coupling sleeve 5 is connected to the locatingelement so that it can rotate but is not able to move axially.Accordingly, the output element 2 is locked to prevent it from rotatingrelative to the coupling sleeve 5 but is able to move axially relativeto the coupling sleeve 5 when it is rotated relative to the locatingelement. The coupling sleeve 5 is not able to move axially expect forwhen the product container 27 is being replaced.

A drive shaft 7 provided at the proximal end of the injection device andforming part of the transmission has teeth 7 a extending radiallyinwardly which constitute a coupling element of the coupling K2. Whenoperated, i.e. when an operating element 15 is pushed in the distal(forward or injection) direction, the drive shaft 7 and as a result alsothe teeth 7 a are moved in the distal direction, as result of which theteeth 7 a locate in the proximal end of the coupling sleeve 5 andestablish a fixed torque-transmitting, positive connection.

A spring element or drive spring 3, which may be provided in the form ofa helical spring or clock spring, is connected to the housing 12 by oneend via a spring sleeve 8 on the external face of the spring 3. Thespring sleeve 8 is prevented from rotating relative to the housing 12but is able to move axially. At the other end, the drive spring 3 isconnected to the drive shaft 7. As a result, energy stored in the spring3 can be output as a rotating movement of the drive shaft 7 relative tothe housing 12. To dispense a product, the energy of the spring element3 is transmitted via the transmission element in the form of a rotatingmovement to the output element so that the latter is screwed relative tothe locating element in the distal direction, i.e. in the dispensingdirection, and pushes the plunger 28, causing the product to bedispensed from the product container 27.

To set a product dose to be administered, a user can rotate the dosesetting element 9 provided in the form of a dose setting button, whichis axially fixed relative to the housing 12. The dose setting element 9is coupled with a coupling element 10 via the coupling K3 so that it isprevented from rotating. The coupling K3 is formed by webs or grooves orteeth of the dose setting button 9, which co-operate in a positive fitwith webs or grooves or teeth of the coupling disc 10 to establish acoupling which can be released by a movement of the coupling element 10in the distal direction. The coupling element 10 can be moved and thusreleased by operating the operating element 15. When in a state of notbeing operated, the coupling K3 is held in a coupled state and thecoupling K2 in an uncoupled state by a spring element 19, which pushesthe drive shaft 7 in the proximal (rear or rearward) direction. Duringthe dose setting operation, the coupling K3 is coupled, i.e. a rotatingmovement of the dose setting button 9 is transmitted to the couplingelement 10. The coupling element 10 is connected to the drive shaft 7 sothat it can not move axially and can not rotate and could also be anintegral part of the drive shaft 7. The rotating movement of the dosesetting element 9 is not transmitted to the coupling sleeve 5 becausethe coupling K2 is uncoupled.

When the drive shaft 7 is rotated, the drive spring 3 connected to thedrive shaft 7 is tensed. To prevent the dose setting button 9 from beingturned back due to the drive spring 3 as it is tensed during the settingoperation, a ratchet 11 or a ratchet mechanism, which may comprise aratchet spring 11 a, e.g. for clamping retaining elements, may beprovided between the housing 12 of the injection device, the componentsof which might, for example, be a mechanical holder 12 a and amechanical holder 12 b and the dose setting button 9. The ratchetmechanism may be designed so that a rotation and/or a tensing of thedrive spring 3 is possible in only one direction. In some preferredembodiments, however, the ratchet mechanism is designed so that therotating action is possible in both directions, e.g. tensing andrelaxing of the drive spring 3. Due to the fact of being able to rotatein both directions, a product dose can be both increased and reducedwhen setting the product dose. A currently set product dose can be readthrough the window 12 d of a display barrel 4.

The rotating movement of the drive shaft 7 is also transmitted to thethreaded sleeve 13, which is connected to the drive shaft 7 so that itis not able to move axially or rotate and may also be an integral partof it. The threaded sleeve 13 has at least one groove on its externalcircumference 13 a in which at least one web 4 a of the display barrel 4locates so that a rotating movement of the threaded sleeve 13 istransmitted to the display barrel 4 by the anti-rotation coupling,permitting an axial relative movement between the display barrel 4 andthreaded sleeve 13. The display barrel 4 has a thread 4 b on itsexternal face which locates in an internal thread 12 c of the housingpart 12 b so that the display barrel 4 is moved due to a rotatingmovement in the axial direction relative to the housing 12, e.g. in thedistal direction. In some preferred embodiments, the display barrel 4moves in the distal direction of the injection device (towards the leftin FIG. 1) during the process of setting and priming the dose byrotating the dose setting button 9. A marking may be provided on theexternal face of the display barrel 4, such as print, a dose display ora scale, which can be read through an opening or a window 12 d in thehousing 12 b of the injection device, and the marking of the displaybarrel 4 is moved relative to the window 12 d. The display barrel 4 hasa rotation stop on its distal end acting in the circumferentialdirection which moves into an abutting contact with a co-operatingcomplementary stop disposed on the housing part 12 a on reaching themaximum dose. The complementary stop is formed by a terminal end of anannular gap of the housing part 12 a. An advantage of using a stop whichacts in the circumferential direction rather than an axial stop is thatthe forces acting on the stop are weaker. The display barrel 4 also hasanother rotation stop on its proximal end acting in the circumferentialdirection, which moves into an abutting contact with a co-operatingcomplementary stop on the housing 12 b on reaching a minimum dose. Thecomplementary stop is formed by the proximal end of the thread 12 c.

Once the dose has been set and the drive spring 3 primed by rotating thedose setting button 9, the setting operation is complete. In somepreferred embodiments, the dose is primed as the spring 3 is tensed. Tocorrect or adjust the dose, the dose setting button 9 simply has to berotated in the opposite direction, e.g. to reduce a dose which mighthave been set too high. In some embodiments, the ratchet 11 may bedesigned as illustrated in FIGS. 14 and 15 of patent applicationPCT/CH2007/000243 and/or US Publication 2009/0254035, the teachings ofwhich are incorporated herein by reference.

During the dispensing process, which is triggered by depressing the pushbutton 15, the display barrel 4 is rotated back in the oppositedirection and is moved back in the proximal direction due to the threadengagement with the internal thread 12 c of the injection device (to theright in FIG. 1). As this happens, it reaches a stop of the displaybarrel 4 acting in the circumferential direction on the housing of theinjection device, e.g. on the housing part 12 b. In an unbrakeddispensing movement in which the threaded rod 2 is moved in the distaldirection without any opposing force, e.g. when no product container hasbeen inserted, this operation may result in too high a strain and, in anextreme situation, deformation or even damage to the display barrel 4 orco-operating part 12 b. A brake mechanism (e.g. comprising brakeelements, e.g. shoe halves and disc 17, 18) acting on the drivingmovement is therefore provided, which will be described below.

The coupling K1, comprising the coupling element acting as a lock sleeve14 and the coupling sleeve 5, is used to couple the coupling sleeve 5with the housing 12 so that it can not rotate in specific operatingmodes or to release it to permit a rotation relative to the housing 12.The coupling K1 is uncoupled when the product container 27 is beingreplaced to enable the output element 2 to be pushed back or screwed inthe proximal direction again and to enable the output element 2 to bescrewed in the distal direction while product is being dispensed. Thecoupling K1 is coupled when the product container is attached to thedrive unit and the operating element 15 is not being operated. Thecoupling K1 is provided in the form of teeth on the external face of thecoupling sleeve 5, which mesh in teeth on the internal face of the locksleeve 14. As a result, the coupling sleeve 5 is prevented from rotatingrelative to the lock sleeve 14. The lock sleeve 14 is mounted in theinjection device so that it can not rotate but can move axially relativeto the housing 12 and the coupling sleeve 5.

During a dispensing operation, the threaded sleeve 13 is moved in thedistal (forward or injection or delivery) direction by operating theoperating element 15. As this happens, the threaded sleeve 13 pushes onthe bearing 29, which is provided in the form of a ball bearing in thisexample but may also be a simple slide bearing, so that the bearing 29pushes against the lock sleeve 14, thereby moving it in the distaldirection for a dispensing operation, and holds it in a distal positionduring a dispensing operation. The coupling element 14 is thereforedisposed distally of the projections of the coupling sleeve 5 for thecoupling K1. As a result, the coupling K1 remains uncoupled for theduration of the dispensing operation.

When the operating element 15 is operated, the couplings K1, K2 and K3operate as follows. By depressing the push button 15 seated on thecoupling element 10 and/or drive shaft 7, the coupling element 10 ispushed in the distal direction together with the push button 15 and thedrive shaft 7. As a result, the coupling K2 is coupled so that the driveshaft 7 is prevented from rotating relative to the coupling sleeve 5.The coupling K1 is then uncoupled due to the movement of the lock sleeve14, against which the threaded sleeve 13 connected to the drive shaft 7pushes via the axially displaceable bearing 29. Alternatively, thecouplings K1 and K2 may be connected in the reverse sequence.

Once K2 is coupled and K1 is uncoupled, the coupling K3 is alsouncoupled due to the movement of the coupling element 10 relative to thedose setting button 9. The coupling element 10, which is connected tothe drive shaft 7, is able to rotate relative to the housing 12 once thecoupling K3 is uncoupled. The energy or force stored in the drive spring3 during priming can be transmitted to the drive shaft 7. Accordingly, atorque is applied to the drive shaft 7, which is transmitted by thecoupled coupling K2 to the coupling sleeve 5, which rotates in unisonwith the drive shaft 7 and transmits this rotating movement to theoutput element 2, which is coupled with the coupling sleeve 5 so that itcan not rotate. The output element 2, provided in the form of a threadedrod in this example, converts the rotating movement into an axialmovement in the distal direction due to the thread engagement 2 a, 6 awith the locating element (comprising elements 6, 26), so that theflange 1 provided on the distal end of the threaded rod 2, which mayalso be construed as part of the output element, is moved in the distaldirection of the injection device.

Since, during the product dispensing operation, the threaded sleeve 13moves in the direction opposite that in which it moves during priming,the display barrel 4 likewise moves in the direction opposite that ofthe priming operation.

In the normal situation, i.e. when a pre-set product dose has been fullydispensed, the dispensing operation and the movement of the outputelement 2 in the distal direction continues until the display barrel 4makes contact with the above-mentioned stop acting in thecircumferential direction. In some embodiments, this happens when thevalue which can be read through the window 12 d has been rotated back to0.

In the situation in which the user of the device releases the operatingelement 15 as the product is being dispensed, the couplings couple inthe order which is the reverse of that in which they uncoupled orcoupled during operation. The product dispensing operation isinterrupted, as a result of which the value may be seen through thewindow 12 d represents the amount still to be dispensed had the pre-setdose been fully dispensed. The product dispensing operation can becontinued by depressing the operating element 15 again, and dispensingcan be stopped again by releasing the operating element 15 or the usercan wait until the product has been fully dispensed.

In the situation in which the product container contains less productthan the maximum dose indicated on the display barrel, the injectiondevice based on this example has an additional device for limiting themaximum dose which can be set for the last time, to prevent thepossibility of a bigger product dose being set than that which is stillin the container. To this end, a traveller 30 is provided, which atleast partially surrounds the coupling sleeve 5 and locates with thecoupling sleeve 5 in such a way that the traveller 30 is not able torotate relative to the coupling sleeve 5 but is able to move axially.The traveller 30 also locates or is positioned by a thread on itsexternal circumference that engages with an internal thread of thethreaded sleeve 13. This arrangement causes an axial movement of thetraveller 30 when there is a relative rotation between the threadedsleeve 13 and coupling sleeve 5, and when there is no relative rotationthe traveller 30 does not effect an axial movement. When setting aproduct dose, the threaded sleeve 13 turns relative to the couplingsleeve 5 so that the traveller 30 moves in the proximal direction.During dispensing, on the other hand, no relative movement takes placebetween the coupling sleeve 5 and threaded sleeve 13 due to the coupledengagement of the coupling K2. Accordingly, the traveller does not move.After setting doses and dispensing product several times, the traveller30 moves into an abutting contact with the drive shaft 7, so that it isno longer possible to increase the dose, even if the display wouldactually permit this.

The user can replace the product container 27 with a new one. To thisend, the product container holder 16 may be removed by rotating thedrive unit relative to the housing 12. As the product container 27 ismoved from the secured position into the non-secured position, e.g. asthe bayonet fitting is released, the locating element is moved togetherwith the output element 2 and the coupling sleeve 5 in the distaldirection relative to the housing 12 and to the coupling element 14,thereby releasing the coupling K1. The projections of the couplingsleeve 5 pointing radially outwardly to establish the coupling K1 arenow disposed distally of the coupling element 14. The output element 2can now be screwed into the drive unit with a relatively slight forceacting in the proximal direction because the thread of the outputelement is not retained by friction. As the output element 2 is screwedback, the coupling sleeve 5 is turned relative to the threaded sleeve 13and so in the direction opposite that during product dispensing, causingthe traveller 30 to be pushed back in the distal direction again. Thescrewing-back operation may take place against the force of a springelement, at least across a part of the total distance, which tries topush the output element in the distal direction, for example. The springelement may act or be disposed between the output element 2 and thedrive shaft 7 for example. Other possible spring elements will bedescribed below specifically with reference to FIG. 6. It is generallypreferred if the force of such a spring element is weaker than the forceneeded to produce an interaction via the plunger from the output element2 onto the product.

Also during the process of removing the product container 27, theretaining element 25 used to secure the product container 27 in theproduct container holder 16 is pushed in the distal direction by thespring 19 until it makes contact with the locating element 6, 26. Thiscontact prevents the spring 19 from fully relaxing when the productcontainer 27 is removed. This is of advantage because the spring 19should be able to apply sufficient force to hold the coupling K3 in acoupled engagement even when a product container 27 has been removed.

By virtue of another aspect, a spring-mounted flange may be used, asillustrated in FIG. 6 for example.

After replacing the product container 27, e.g. an ampoule, capped vialor the like, the user is prompted to proceed with priming, as may bedescribed in operating instructions. This is useful on the one handbecause there may be air in the product container 27 and on the otherhand because the output element 2 may have been previously pushed fullyinto the drive unit and a certain amount of clearance may have beencreated between the plunger 28 and the flange 1 due to the differentlevel to which the product container 27 is filled.

FIG. 6 illustrates an output element 2 with a flange 1 attached to itsfront or distal end, which is non-displaceably connected to the threadedrod. Disposed between the flange 1 and the threaded insert 6 illustratedin FIG. 6 is a spring element 38, which may be provided in the form ofresilient arms 38 a extending out at an angle, for example. Theseresilient arms 38 a may be secured to the flange 1 or/and to thethreaded insert 6. Another option would be to injection mold a suitableelastomer onto the flange 1 or/and onto the threaded insert 6. After anew product container 27 has been inserted, a clearance may occurbetween the flange 1 and the plunger 28, which may be attributable to adifference in the level to which product containers 27 have been filledwhen full, given that they have a certain tolerance.

After pushing in the flange 1 connected to the threaded rod 2, theflange 1 based on the embodiment illustrated in FIG. 1 lies directlyagainst the threaded insert 6.

In the embodiment illustrated in FIG. 6, the at least one spring element38 has pushed the flange 1 away from the threaded insert 6 in the distaldirection by a predefined distance. This means that when a productcontainer 27 has been inserted or while a product container 27 is beinginserted, the flange 1 will move into contact with the proximal end ofthe plunger 28, even if the plunger 28 is pushed into the productcontainer 27 by differing distances caused by manufacturing tolerancesof different product containers. Conventional means for eliminating theclearance between the flange 1 and plunger 28 are therefore no longerabsolutely necessary and may even be dispensed with, for example.

As may be seen from FIG. 1, the injection device, e.g. the drive unit,comprises a brake (which may be thought of as comprising brake elementsor components 17, 18) which decelerates a rotating part, in this examplethe transmission element or/and the driving movement. If conventionalinjection devices are used incorrectly, i.e. if no product container hasbeen inserted, but the device is nevertheless operated, there is a riskof placing too high a strain on or even damaging the components of theinjection device. When a product container 27 is inserted, the forcesand movements which occur are damped by the viscosity of the productduring the product dispensing operation. In the absence of a productcontainer, there is no such damping effect. It is the brake inaccordance with the present invention which is used for this purpose,thereby preventing excessive strain.

FIGS. 7A, 7B and 8 are diagrams on a larger scale illustratingembodiments of a brake mechanism suitable for the device illustrated inFIG. 1, e.g. a first and second embodiment, respectively, each of whichoperates in a similar manner. The first embodiment illustrated in FIGS.7A, 7B has two brake shoe halves 17 latched to one another so that theycan not rotate and so that they can also not move axially, which haveprofiled portions directed toward one another, between which an annulargap is formed in which a brake disc 18 is accommodated. The annular gapis of a defined width and, in an alternative arrangement, the brake shoehalves could move axially relative to one another. The brake shoe 17could be of an integral design. The brake disc 18 is accommodated sothat it can not rotate relative to the housing 12 but can move axially,due to the profiled external circumferential surface of the brake disclocating in a profiled inner circumferential surface of the housing part12 b. At least one brake shoe half 17 or the entire brake shoe ismounted at least so that it can not rotate in the drive train ortransmission element. The sleeve-shaped brake shoe 17 has projectionspointing radially inwardly, which locate in a matching profile of thedrive sleeve 7. The brake disc 18 is able to move between the brake shoehalves 17. The brake disc 18 is mounted so that it can not rotate, e.g.is guided in a groove, and so that it is able to move axially in theinjection device or housing part 12 b. The brake disc 18 is toothed onthe top and bottom face with teeth 18 a, 18 b on the end face projectingcircumferentially in both directions and having an identical ordifferent tooth height ZH, and is mounted or displaceably clampedbetween the threaded sleeve 13 and the brake shoe 17, e.g. with a smallclearance of approximately a tooth size or tooth height ZH or bigger,the latter having co-operating complementary teeth 13 b respectively 17a, e.g. with a corresponding or identical tooth height ZH.

Due to the fixed torque-transmitting connection between the transmissionelement (which, again, may be thought of and/or referred to ascomprising elements 7, K2, 5) during a dispensing operation or when whatmay be thought of and/or referred to as “firing blank,” i.e. when noproduct container has been inserted, the brake shoe 17 is moved inrotation relative to the brake disc 18. When this happens, thedisposition of the brake shoe teeth 17 a, 17 b ensure that the brakedisc 18 oscillates axially between the threaded sleeve 13 and the brakeshoe 17. As a result, the distal teeth 18 a and proximal teeth 18 b ofthe brake disc 18 move alternately into contact with the co-operatingcomplementary teeth 17 b and 17 a. Due to one or more of the resultantfriction, elastic deformation and the oscillating mass, a correspondingloss occurs, thereby limiting the maximum angular speed ω of therotating parts 13 and 17.

The embodiment illustrated in FIG. 8 operates on a similar principle,the difference being that one of the two brake shoe halves and/or itsend-face tooth profile is formed by the transmission element or thethreaded sleeve 13 connected to the transmission element so that itcannot rotate. A fixed, defined distance may be provided between theprofiles 17 a and 13 b, or alternatively a variable distance, becausethe brake shoe half 17 is able to move axially relative to the threadedsleeve 13. Due to the spring 19, the profiles 13 b and 17 a can bepushed toward one another so that they move into a meshing contact withthe profiles 18 a and 18 b.

Due to the vibration or oscillation of the brake disc 18 between thethreaded sleeve 13 and brake shoe 18 which increases with the angularvelocity ω, the braking force increases disproportionately as theangular velocity ω increases, so that the curve BS of braking forcesschematically illustrated in FIG. 9 can be achieved.

FIG. 9 is a schematic illustration plotting the curve of the brakingforce which can be achieved by a brake mechanism in accordance with thepresent invention, from which it may be seen that the braking forcerises to an increasing degree with the angular or rotational velocity ω.In some preferred embodiments, the braking force is relatively low orzero up to the maximum permissible angular velocity ω_(max) and risessharply with effect from the maximum permissible angular velocityω_(max).

FIG. 10 illustrates the angle of rotation of the display barrel 4 as afunction of time, which is able to effect three full revolutions(3×360°) in the embodiments illustrated as an example. As may be seenfrom FIG. 10, the display barrel 4 has completed three full revolutionsafter the time t_(non-braked), which is shorter than the timet_(invention) in the case of a decelerated rotating movement of thedisplay barrel 4 during which the angle of rotation increases linearlyas a function of time.

Due to the braking force generated by the oscillating brake disc 18, themaximum possible angular velocity ω_(max) of a dispensing movement canbe reduced or limited so that the backward-rotating display barrel 4 isable to move into an abutting contact with the stop acting in thecircumferential direction or the housing part 12 b at only a maximumspeed predefined by the brake. If the brake is designed accordingly, themaximum possible contact speed of the display barrel 4 is so low thatthere is little chance of deformation or damage occurring due to theimpact. Other brake mechanisms may also be used as an alternative to abrake disc 18 oscillating between the threaded sleeve 13 and brake shoe17.

For example, as an alternative or in addition, the brake may be based onanother embodiment in the form of a centrifugal brake as illustrated inFIG. 12. In this case outwardly displaceable brake shoes 41 are mountedon the transmission element or/and the drive shaft 7 and/or another partwhich rotates with the drive shaft 7, for example the coupling element10, the threaded sleeve 13 or the display barrel 4, which have a massand which effect the same rotation as the rotating part. The brake shoes41 may, but need not necessarily, be inwardly or outwardly biased by aspring. The brake shoes may be pivoted or moved radially outwardly bythe centrifugal force to move into a braking engagement with a sleeve42, for example the housing 12. In this embodiment, pins 40 or fastenersextending radially outwardly are provided, the ends of which areprovided with brake pads 41 biased by the spring, for example. When therotation speed of the non-braked or only partially braked rotatingelement is sufficiently high, the brake pads 41 are moved radiallyoutwardly by the centrifugal force, optionally also assisted by thespring-biased support, and can move into contact with an outer staticsleeve 42, thereby producing the desired braking effect due to friction.The outer static sleeve may also be formed by the housing 12 or housingpart 12 b.

In another embodiment illustrated in FIGS. 11A and 11B, the brake may beprovided in the form of an eddy current brake 20, in which case a brakedisc 21 may be connected to a rotating part which has to be decelerated,for example the transmission element, drive shaft 7, threaded sleeve 13or display barrel 4, and the elements interacting with the brake discmay be connected to the housing or an element fixedly disposed on thehousing or to an element rotating relative to the brake disc.

In some preferred embodiments, the brake disc 21 is made from a goodelectrical conductor, such as pure aluminium or copper, for example.Rare earth alloys may be used as the material for the axially magnetisedmagnets 22, neodymium for example. The permanent magnetic field may belinked by a magnet yoke 23 made from iron to the air gap, where itextends through the brake disc 21 as vertically as possible. The brakingforce is created by the surface and flow density in the air gap and therated current in the brake disc 21, for which purpose the surface shouldbe as large as possible, the air gap should be as small as possible andthe disc thickness should be as big as possible. The braking torqueoccurs over the averaged radius (working radius). Brakes may be designedwith several magnet systems which act on a disc 21.

The usual approximation calculations are used to calculate the currentdensity, braking power and hence braking torque of an eddy currentbrake. Leaving aside the effect of the air gap, it is assumed that therewill be a standard cylindrical magnetic flow and it is stipulated as acondition that the pole diameter should be sufficiently small comparedwith the radius of the disc 21. At high speeds, the approximation isinaccurate, among other reasons because the magnetic fields caused bythe eddy currents cause a not inconsiderable feedback and hencenon-linearity.

In some preferred embodiments, the magnets 22 and the magnet yoke 23 areconnected to the housing 12 of the injection device or the housing part12 b or another non-rotating part to be able to generate the desirededdy current braking effect of the brake disc 21.

In another embodiment illustrated in FIGS. 13 and 14, the brake may beprovided in the form of a fluidic or hydrodynamic brake. If a standardfluid is used as the braking medium, the linear braking curve FBindicated in FIG. 4 can be obtained for the eddy current brake. However,if the intention is to achieve a braking force which rises more sharplyas a function of angular velocity ω, so-called non-Newtonian fluids maybe used, as a result of which, unlike a Newtonian fluid, the viscositydoes not remain constant but increases when a shearing force acting onthe fluid is increased, which is the case as the speed increases. Theseare what are known as anomalous viscous fluids.

In the case of the fluidic brake, the braking force is generated by twofluid surfaces moving against one another. In particular, the brakingforce is generated by a fluid volume which is sheared by a relativemovement. The shearing stresses which occur during such movementscorrespond to the braking force. The volume is provided in the form of achamber split into two parts 45 a, 46 a, in which the fluid is disposed.One chamber part 46 a is disposed in a rotating part 46 and the otherchamber 45 a is disposed in a part 45 relative to which the rotatingpart 46 is able to rotate. The part 46 may be connected so as to rotatein unison with the drive shaft 7 or to the transmission element oranother part which rotates when product is being dispensed. The part 45rotates in unison with at least the housing 12 or a stationary part onthe housing. Furthermore, the part 45 may be able to move axially or maybe axially immobile relative to the housing 12. The sleeve-shaped part45 may be thought of and/or referred to as a brake housing and the part46 mounted in the sleeve 45 as a brake shaft. When the brake is in theassembled state, the fluid chamber halves 46 a distributed axiallyaround the external circumference of the brake shaft are axially on alevel with the fluid chamber halves 45 a distributed around the internalcircumference of the brake housing. More, the same number or fewer fluidchamber halves 45 a may be provided than 46 a. In the assembled state, aslim gap is disposed between the internal diameter of the brake housing45 and the external diameter of the brake shaft 46 in the region of eachof the fluid chamber halves 45 a, 46 a, which may be dimensioned so thatfluid is conveyed into the gap or no fluid or virtually no fluid isconveyed into the gap when the brake shaft 46 is rotating relative tothe brake housing 45. The brake housing 45 may be axially sealed at bothends with sliding seal elements 47 so that no fluid is able to escapefrom the brake. The seal elements 47 may be provided in the form of alid. The lid may be provided as a separate part or serve as the couplingshaft, for example.

Embodiments of the present invention, including preferred embodiments,have been presented for the purpose of illustration and description.They are not intended to be exhaustive or to limit the invention to theprecise forms and steps disclosed. The embodiments were chosen anddescribed to illustrate the principles of the invention and thepractical application thereof, and to enable one of ordinary skill inthe art to utilize the invention in various embodiments and with variousmodifications as are suited to the particular use contemplated. All suchmodifications and variations are within the scope of the invention asdetermined by the appended claims when interpreted in accordance withthe breadth they are fairly, legally, and equitably entitled.

1. An injection device for dispensing a product, the injection devicecomprising a moveable element which is moved for a dispensing operation,a spring, a product container holder and a product container, whereinthe spring pushes against the moveable element to move the moveableelement to an initial position after the dispensing operation has endedand against the product container to seat the product container in theproduct container holder.
 2. The injection device as claimed in claim 1,wherein the spring is disposed between the moveable element and theproduct container.
 3. The injection device as claimed in claim 2,wherein the spring is one of a separate part or a part formed by themoveable element.
 4. The injection device as claimed in claim 1, whereinthe spring acts on the product container directly or via a retainer. 5.The injection device as claimed in claim 4, wherein at least one of thespring and the retainer comprises a stop which prevents the spring fromfully relaxing when no product container is inserted.
 6. The injectiondevice as claimed in claim 1, wherein the moveable element comprisespart of a coupling and is moved out of the coupling for a dispensingoperation.
 7. The injection device as claimed in claim 1, wherein themoveable element is able to move axially relative but not rotate.
 8. Theinjection device as claimed in claim 1, further comprising an outputelement which acts on the product to be dispensed to dispense theproduct via a plunger which is moveably accommodated in the productcontainer, and the moveable element is coupled with the output elementso that it blocks a dispensing movement of the output element when theinjection device is in a non-secured state.
 9. The injection device asclaimed in claim 8, wherein the dispensing movement of the outputelement is a rotating movement.
 10. The injection device as claimed inclaim 8, further comprising an axially displaceable operating elementwhich can be operated by a user of the injection device, wherein, whenthe operating element is operated, the moveable element is moved axiallyso that the output element is released for a movement in or opposite adispensing direction.
 11. The injection device as claimed in claim 8,further comprising a locating element which can be moved in an engagedconnection to the output element and between a first position and asecond position, and the output element is uncoupled from the moveableelement in the first position so that the output element can be moved inor opposite a dispensing direction.
 12. The injection device as claimedin claim 11, wherein the locating element is coupled with a fixingdevice so that it is moved axially when the product container is beingsecured or released.
 13. The injection device as claimed in claim 10,wherein the operating element can be re-set by the spring.